Following Thursday's big launch of its new Galaxy S IV, what kind of reaction is Samsung's new phone getting? In general, the reaction is positive, but the question is whether the buzz can last.

Some industry observers are declaring that, given its huge U.S. marketing budget and the success of the Galaxy S III as the most popular Android phone, the S IV is going to be a big seller. The eight-core processor, a slightly larger 5-inch high-resolution screen and the 13-megapixel rear camera certainly help, as does a flood of new features.

On the hardware side, there are several modest improvements. As a sibling to the S III, the IV appears nearly an identical twin. Its plastic casing remains the same, with the IV having a screen that's 0.2 inches larger. The new smartphone is also a bit narrower, thinner, taller and lighter.

The full-HD Super AMOLED screen is garnering praise for sharpness -- 1920x1080 -- and the new device also has the ability to act as an infrared remote control for TVs and other devices. The battery has been increased from 2100 mAh to 2700, and it ships with the latest version of Android, Jelly Bean 4.2.2, featuring Samsung's custom Touch Wiz user interface on top.

Eye Tracking, Airview

There had been a slew of rumors that the S IV would have eye-tracking technology that would automatically scroll Web pages as your eye traveled over the screen. The version shown Thursday is a more modest improvement over the S III's SmartStay, where the screen dimmed if you looked away. The new phone knows when you're looking at the screen, and a user can then tilt the phone up or down to scroll. A Samsung representative has told news media that this feature also detects head placement and how the phone is being held. Additionally, a user can set the phone to pause a video if you look away from the screen.

An Airview feature allows the user to hover a finger over the screen, such as over e-mail, and a preview of the content appears without launching a new screen. New gestural controls enable users to move pages by left/right or up/down hand waves.

The camera function offers a variety of new features, such as the ability to shoot photos with the front and back cameras at the same time, or to add nine seconds of audio to a photo. There's also a built-in pedometer, a humidity/temperature sensor and an included health app. The speakers and display auto-set themselves to provide the clearest dialog or the best reading display for the surroundings.

'Pretty Impressive'

Ross Rubin, principal analyst at Reticle Research, described the new device as "a pretty impressive combination of technologies that is thinner, faster, lighter, with a bigger screen." He noted that there are "a whole lot of proprietary technologies, with varying degrees of usefulness," such as the ability to shoot photos with both cameras at the same time or previewing by hovering your finger.

Current Analysis' Avi Greengart said he expected the S IV "to be a hit," although he did not think its success would affect the success of Apple's iPhone, as shown by the current simultaneous success of the S III and the iPhone.

Greengart added that the"most exciting thing about the new model" was its model number, IV, as that establishes it as the next in a line of well-received smartphones. More specifically, he pointed to the "beautiful display, a faster processor, a big battery improvement and a lot -- a lot -- of new features."

He noted that, while ease of use may get compromised with so many features, Samsung has brought "the setup of many of these new features to the phone setup," so the user is asked if they want to implement X when they set up the phone.